A bipartisan coalition of senators essentially promised Thursday that the U.S. would take military action against Iran if they become capable of producing nuclear weapons. Just don’t ask them to define “capable.”

Thirty-two senators have signed on to sponsor the six-page resolution that “rejects any United States policy that would rely on efforts to contain a nuclear weapons-capable Iran.” Some believe it amounts to a promise that the U.S. would use force against Iran if they become capable of producing nuclear weapons, though what precisely “capable” means is up in the air.

“I guess everybody will determine for themselves what that means,” Sen. Joe Lieberman (I-CT) said at a news conference on the Capitol Hill. “But to me, nuclear weapons capability means that they have crossed a red line and they’re capable of producing a nuclear weapon. In other words, they have all the components necessary to do that. It is a standard that in my opinion is more real, and perhaps in some sense it’s higher than saying the red line is when they actually have the nuclear weapons.”

Lieberman said that Iran has “only two choices: peacefully negotiate to end your nuclear weapons program or expect a military strike to disable that program. Distraction by negotiation why you become a nuclear power is not an option for you, and containment of a nuclear Iran is not an option for us.”